Compact compensating cylinder

Abstract

A compensating cylinder unit for compensating relative movements between a stationary frame and a compensated frame which includes parts of a coiled tubing compensation system. The compensating cylinder unit includes a fluid reservoir configured to connect to the stationary frame, and a compensating cylinder configured to connect to the compensated frame, to at least partly enclose the fluid reservoir, and to be in a fluid communication with the fluid reservoir to allow for an axial displacement of the compensating cylinder relative to the fluid reservoir.

What is claimed is: 
     
         1 - 20  (canceled) 
     
     
         21 . A compensating cylinder unit for compensating relative movements between a stationary frame and a compensated frame comprising parts of a coiled tubing compensation system, the compensating cylinder unit comprising:
 a fluid reservoir configured to connect to the stationary frame; and   a compensating cylinder configured to connect to the compensated frame, to at least partly enclose the fluid reservoir, and to be in a fluid communication with the fluid reservoir to allow for an axial displacement of the compensating cylinder relative to the fluid reservoir.   
     
     
         22 . The compensating cylinder unit as recited in  claim 21 , wherein,
 the fluid reservoir comprises a first fluid reservoir end which comprises an opening, and   further comprising:   a gas reservoir comprising a second gas reservoir end; and   a connection element attached to the second gas reservoir end and arranged into the opening of the first fluid reservoir end of the fluid reservoir so as to provide an axial interconnection between the gas reservoir and the fluid reservoir,   wherein, the compensating cylinder is further configured to slide around a circumference of the connection element.   
     
     
         23 . The compensating cylinder unit as recited in  claim 22 , wherein the first fluid reservoir end of the fluid reservoir further comprises a protruding fluid reservoir flange. 
     
     
         24 . The compensating cylinder unit as recited in  claim 22 , wherein the connection element comprises at least one pressure equalizing channel configured to enable a fluid communication between the fluid reservoir and the gas reservoir. 
     
     
         25 . The compensating cylinder unit as recited in  claim 22 , wherein,
 the first fluid reservoir end further comprises an inner radial surface,   the connection element comprises a protruding piston flange which comprises an outer radial surface, and   the connection element is configured to releasably interconnect the second gas reservoir end to the first fluid reservoir end through abutment of the outer radial surface of the protruding piston flange against the inner radial surface of the first fluid reservoir end.   
     
     
         26 . The compensating cylinder unit as recited in  claim 25 , wherein,
 the first fluid reservoir end further comprises an outer surface,   the compensating cylinder comprises a first axial cylinder end which comprises an inner surface,   the compensating cylinder, the gas reservoir, and the fluid reservoir are each configured to be axially displaceable, the axial displacements being confined between,
 an operational configuration where the gas reservoir is locked to the fluid reservoir, and 
 a transport configuration where the outer surface of the first fluid reservoir end abuts the inner surface of the first axial cylinder end of the compensating cylinder ( 1 ), and where the gas reservoir is axially released from the fluid reservoir. 
   
     
     
         27 . The compensating cylinder unit as recited in  claim 26 , further comprising:
 a connection element comprising a surface, the connection element being fixed to the second gas reservoir end of the gas reservoir and arranged into the opening of the first fluid reservoir end of the fluid reservoir so as to provide an axial interconnection between the gas reservoir and the fluid reservoir,   wherein,   the fluid reservoir further comprises a second fluid reservoir end which comprises an inner radial surface, and   the transport configuration includes an abutment of the surface of the connection element towards the inner radial surface of the second fluid reservoir end of the fluid reservoir.   
     
     
         28 . The compensating cylinder unit) as recited in  claim 27 , wherein,
 the compensating cylinder comprises a volume, and   further comprising:   a fluid channel configured to provide a fluid communication between the fluid reservoir and the volume within the cylinder arranged outside of the fluid reservoir.   
     
     
         29 . The compensating cylinder unit as recited in  claim 28 , wherein the fluid channel is further configured to extend from the second fluid reservoir end) of the fluid reservoir to the volume within the cylinder situated outside the fluid reservoir. 
     
     
         30 . The compensating cylinder unit as recited in  claim 29 , wherein the fluid channel comprises a through-going accumulator passage which is configured to penetrate the second fluid reservoir end. 
     
     
         31 . The compensating cylinder unit as recited in  claim 28 , wherein the fluid channel further comprises a fluid guiding feeding tube configured to extend from the second fluid reservoir end of the fluid reservoir. 
     
     
         32 . The compensating cylinder unit as recited in  claim 31 , wherein,
 the connection element further comprises at least one radial channel, the connection element being arranged into the opening of the first fluid reservoir end of the fluid reservoir so as to provide an axial interconnection between the gas reservoir and the fluid reservoir,   wherein,   the fluid guiding feeding tube comprises at least one radial bore which is alignable to the at least one radial channel to provide a fluid communication between the fluid guiding feeding tube and the volume within the cylinder situated outside the fluid reservoir and the gas reservoir.   
     
     
         33 . The compensating cylinder unit as recited in  claim 26 , wherein,
 the gas reservoir further comprises outer walls,   the first fluid reservoir end further comprises an outer radial surface which is arranged to face the first axial cylinder end of the compensating cylinder, and   the compensating cylinder further comprises inner walls and axial walls which are configured to slidingly surround the connection element, the second gas reservoir end and the first fluid reservoir end so as to form a fluid tight first cylinder chamber which is bounded by at least the inner walls of the compensating cylinder, the outer walls of the gas reservoir, and the outer radial surface of the first fluid reservoir end facing the first axial cylinder end of the compensating cylinder.   
     
     
         34 . The compensating cylinder unit as recited in  claim 33 , wherein,
 the fluid reservoir further comprises outer walls, and   the first fluid reservoir end further comprises a protruding fluid reservoir flange comprising an outer radial surface which is arranged to face away from the first fluid reservoir end, the protruding fluid reservoir flange being configured to provide a second cylinder chamber which is bounded by at least,
 the inner walls of the compensating cylinder, 
 the outer walls of the fluid reservoir, and 
 the outer radial surface of the protruding fluid reservoir flange of the first fluid reservoir end facing away from the first fluid reservoir end. 
   
     
     
         35 . The compensating cylinder unit as recited in  claim 34 , further comprising:
 a pressure control device configured to provide pressure adjustments within the second cylinder chamber,   wherein, the second cylinder chamber is connected to the pressure control device.   
     
     
         36 . The compensating cylinder unit as recited in  claim 34 , further comprising:
 a fluid channel configured to provide a fluid communication between the fluid reservoir and the fluid tight first cylinder chamber, the fluid channel comprising,
 a through-going accumulator passage configured to penetrate the second fluid reservoir end of the fluid reservoir, 
 a valve device arranged outside the fluid reservoir to be in a fluid communication with the through-going accumulator passage, and 
 a fluid guiding feeding tube comprising a first longitudinal end arranged to be in a fluid communication with the fluid tight first cylinder chamber during operation, and a second longitudinal end arranged to be in a fluid communication with the valve device. 
   
     
     
         37 . A method for altering a compensating cylinder unit from an operational configuration to a transport configuration, the compensating cylinder unit comprising:
 a compensating cylinder comprising a first axial side and a second axial side,   a fluid reservoir, and   a gas reservoir interconnected in a fluid communication with the fluid reservoir,   the compensating cylinder being in fluid communication with the fluid reservoir to allow for an axial displacement of the compensating cylinder relative to the fluid reservoir,   the method comprising:   venting each of a first volume within the compensating cylinder, a second volume in the fluid reservoir, and a third volume in the compensating cylinder to an ambient pressure; and   applying an external contraction force on at least one of the first axial side and the second axial side of the compensating cylinder unit to axially displace the gas reservoir relative to the fluid reservoir.   
     
     
         38 . The method as recited in claim  17 , wherein that the compensating cylinder unit comprises:
 a fluid reservoir configured to connect to the stationary frame; and   a compensating cylinder configured to connect to the compensated frame, to at least partly enclose the fluid reservoir, and to be in a fluid communication with the fluid reservoir to allow for an axial displacement of the compensating cylinder relative to the fluid reservoir.   
     
     
         39 . A coiled tubing compensation system comprising:
 a stationary frame;   a compensated frame; and   the compensating cylinder unit as recited in  claim 21 ,   wherein,   the stationary frame is configured to connect to the fluid reservoir, and   the compensated frame is configured to connect to the compensating cylinder.   
     
     
         40 . The coiled tubing compensation system as recited in claim  19  comprising at least two compensating cylinder units arranged so as to have their respective longitudinal axes arranged in parallel.